The present invention relates to articulated or hinged floating box caissons provided with means for unfolding or spreading the elements thereof from a transport position to an operative position.
It is the primary object of the present invention to provide a hinged box caisson and control structure therefor, the arrangement being such that the ratio of the overall width of the caisson in its transport position to the width in its operative position will be approximately 1:3.
A floating box caisson according to the instant invention comprises a central caisson and a pair of lateral caissons each associated with an end ballast, these elements being adapted, in the transport position, to be folded on one another. The floating caisson includes a system for straightening the ballasts and another system for unfolding the lateral caissons. Such systems are designed such that they are capable of rotating the lateral caissons through an angle of 180.degree. and of simultaneously straightening the end ballasts, such movements being obtained by using a single actuator.
According to an essential feature characterizing this invention, the system for unfolding the lateral caissons comprises a cylinder, a rocker and a link assembly, and the system for straightening the ballasts comprises a constant-length rope system interconnecting a fixed point of the central caisson to a fixed point of the respective ballast. Operation of the cylinder simultaneously causes the unfolding of the lateral caissons and the straightening of the end ballasts.
According to a further feature characterizing this invention the constant length rope system includes means for taking up slack in the rope, notably when the component elements of the floating caisson are in their transport or folded position. These means may consist for example of a spring-urged arm pivoted at one end to a fixed point of the end ballast, the rope passing around the opposite or free end of the arm.